Hurrah for Product Claims

“Biogen” insufficiency has been an accursed ground of patent insufficiency ever since introduced in 1997 by Lord Hoffman’s ruling in Biogen v Medeva. Since then, it has been open for a defendant to allege that a patent claim is overbroad by pointing to something within the scope of the claim and alleging that it “owes nothing to the teaching of the specification”. The Court of Appeal revisited the doctrine in Amgen in 2002 but fell far short of reining it back. It has taken the unusual occasion of Lord Hoffman coming down to sit in the Court of Appeal to tell us all that he has been mis-interpreted over the years (and not for the first time if we recall his rescinding of the “Protocol Questions” for infringement). The English Patents Court has been seen in recent years to be quite “anti-patentee”. This decision is a welcome step in restoring balance.

The EPO has no doctrine directly equivalent to Biogen insufficiency. For an opponent before the EPO to argue insufficiency on the grounds that the patent monopoly is broader than is justified by the description, it is necessary to show that the claim is an obvious desideratum or to identify a missing essential feature. Nevertheless, insufficiency has been one of the main grounds that the EPO has been using to limit claim scope in the biotech field. With the EPO President openly saying that their aim is to grant better (narrower?) patents, and the English Court of Appeal saying there are claims the validity of which “will be particularly sensitive to the context of the teaching of the patent and the prior art”, patent attorneys and their clients will need to sharpen their pencils to ensure that claims are both broad and valid.

The patent in question in this case concerned an enantiomer of citalopram, which is an anti-depressant in the class known as selective serotonin re-uptake inhibitors (SSRIs), of which ProzacTM and SeroxatTM are the best known examples. Citalopram was originally patented by the Danish company H Lundbeck A/S, but the patent expired several years ago.

Citalopram is a “racemate” in that it comprises equal quantities of two mirror-image isomers, otherwise known as stereoisomers or enantiomers. As has been routine for at least two decades, medicinal chemists seek to resolve racemates to determine which (if either) enantiomer has more activity (or less toxicity – recall ThalidamideTM). Patents for the enantiomers often follow some time after the patents for the underlying formulae and represent very valuable extensions of the term of protection for the drug companies. The UK High Court is now accustomed to battles over patents for enantiomers (see Ranbaxy v. Warner-Lambert discussed in the Spring 2006 edition of this newsletter, and the topic “Stereochemistry” in that edition).

It was known that (+) and (-) enantiomers of citalopram existed. (Of course, it was not known which might be preferred, although this would readily become apparent once they were separated or ‘resolved’.) The challenge was either to resolve them, or to resolve an intermediate product, from which the pure enantiomers of citalopram could be made. There were many ways available to a chemist to try the former, and several possible ways to try the latter.

There was a seven-year gap before a way of resolving the enantiomers was devised. When this was achieved, it was found that all the re-uptake inhibitor activity was due to the (+) enantiomer. Lundbeck named it Escitalopram. (More recently it has been shown that the (-) enantiomer actually slows down the inhibitory effect.) The patent for the first time described how to succeed. The question was “did this entitle the inventors to a patent for the product or just to the method of making it?”

At trial, the claims to the product were held to be invalid for insufficiency. The trial judge said “everyone knew that the two enantiomers existed and that one or other or both had a medicinal effect. What Lundbeck discovered was one way of making it. But that did not entitle them to a monopoly of every way of making it.” The judge was applying the principals of the House of Lords 1997 decision in Biogen v Medeva discussed in the “Articles” section of our newly relaunched website (http://www.jenkins.eu/articles/biogen-insufficiency-.asp).

In Lord Hoffman’s opinion, therefore, the decision in Biogen is limited to the form of claim which the House of Lords was there considering, and cannot be extended to an ordinary product claim in which the product is not defined by a class of processes of manufacture.

It is true that the House in Biogen endorsed the general principle stated by the Board of Appeal in EPO Board of Appeal Desicions T409/91 Fuel Oils/EXXON [1994] OJ EPO, that —

the extent of the patent monopoly, as defined by the claims, should correspond to the technical contribution to the art in order for it to be supported or justified.

The judge in Lundbeck said that in holding claim 1 insufficient, he was applying this principle. But then he treated the relevant “technical contribution to the art” as being the inventive step, namely a way of making the enantiomer. In Lord Hoffman’s opinion, that was a mistake. “When a product claim satisfies the requirements of section 1 of the 1977 Act, the technical contribution to the art is the product and not the process by which it was made, even if that process was the only inventive step.”
Biogen should therefore not be read as casting any doubt upon the proposition that an inventor who finds a way to make a new product is entitled to make a product claim, even if its properties could have been fully specified in advance and the desirability of making it was obvious.

EPO cases such as Kawasaki Steel Corporation and Du Pont made it clear that if the product satisfies the requirements of novelty and inventive step, the “technical contribution” is the product. However, there is no statutory link between “sufficiency” and “inventive step”.

There are obviously arguments of public policy on both sides: The Kawasaki Steel line of cases shows that sometimes the “real invention” does not lie in the discovery of the new substance but in finding a process of manufacture. But Parliament has chosen to allow product claims, and the jurisprudence of the EPO, which we have always regarded as carrying great weight, shows that such claims can be made in the latter case as well. It is too late to have regrets about the breadth of the monopoly which the claims confer.

Lord Justice Jacob gave a concurring but separate opinion. He seems to prefer not to dismiss Biogen as applying only to the facts of its case (product-by-process claims). He gave the example where a man may find a particular way of making a new substance which is 10 times harder than diamond. According to Jacob LJ, he cannot just claim “a substance which is 10 times harder than diamond.” He can claim his particular method and he can claim the actual new substance produced by his method, either by specifying its composition and structure or, if that cannot be done, by reference to the method but no more. The reason he cannot claim more is that he has not enabled more – he has claimed the entire class of products which have the known desirable properties yet he has only enabled one member of that class. Such a case is to be contrasted with the present where the desirable end is indeed fully enabled – that which makes it desirable forms no part of the claim limitation.

Comment

Any other decision would have eviscerated the pharmaceutical industry. Not only would a swathe of enantiomer patents be invalid, but also claims to other “desirable” but not yet isolated molecules – a wide sphere in the present day industry in which molecules are designed in theory and their effects are predicted before they are synthesized.

Is ‘Biogen Insufficiency’ dead? Lord Hoffman’s judgement seems to limit Biogen to almost nothing – just product-by-process claims (which are of very limited value following the Court of Appeal ruling in Amgen), but Jacob LJ’s opinion will carry more weight. He may not be quite so venerable, but it is before him that appeals will be heard on a day-to-day basis. Jacob LJ does not seem to want to let it go so completely. He concedes there may be cases between one extreme (a novel substance) and another extreme (“free beer”) where the invention may lie in appreciating that a particular combination of desirable properties is of special value, and he concedes “the validity of that sort of claim will be particularly sensitive to the context of the teaching of the patent and the prior art.”

The Amgen Court of Appeal has already said that Biogen insufficiency is not a separate ground of insufficiency, and there is only one kind of insufficiency - see the Spring 2002 edition of this newsletter. At that time we said it was not very helpful guidance. And Biogen insufficiency will not go away. Lord Hoffman says it applies only in rare cases. But it seems Biogen can still be argued if the claim is to a class or genus. Most claims try to claim a class. In this instance it seems that Lord Hoffman has backtracked and said that Biogen claimed a class because of the word “recombinant” (all members of the class of artificially created DNA).

One might take the view that the Court of Appeal has simply carved out an exception to Biogen. The exception is for product claims defined by their structure (rather than defined as a class of products that perform a common function). The existence of the (+) enantiomer was known, but no-one had yet devised a way of making it in isolation.  Lundbeck were the first, and Parliament intended that this should entitle Lundbeck to a monopoly in the product, howsoever it is made.

Perhaps ‘obviously desirable goal’ has no place in patent sufficiency, but does that mean you can claim the known desideratum just because you are the first to achieve it? It seems to hinge on a fine distinction between a goal that is known to exist (or is obvious) but has never been achieved, and a product that is known (or is obvious) but has never been reduced to practice.

So the critical words are perhaps “Lundbeck’s claim was to a single product”. You first have to decide if you have a claim to a single product or a class of products. If the former then, OK, there is only one kind of insufficiency. If the latter well, hey, you still have Biogen insufficiency to consider.





Biogen Revisited
In Biogen the DNA molecule that expresses the antigens of the hepatitis B virus was not new, so the inventor in that case (Professor Murray) could not claim it. Not only did it exist naturally in people suffering from hepatitis B, but it had also been isolated outside the human body by purification of samples of the infective agent. Prof. Murray had invented a process for making the DNA. But simply patenting the process would not give much of a monopoly, because the science was rapidly advancing, and scientists would find other methods of making the antigens, outside the scope of any process claim he could justify (as indeed happened).
What Prof. Murray’s patent attorney tried to do therefore, was to make a product claim to a DNA molecule which defined the product partly by the way it had been made and partly by what it did, namely to express the antigens. It was a hybrid or “product-by-process” claim. Such claims are relatively rare since Kirin-Amgen Inc v Hoechst Marion Roussel discussed in the Autumn 2002 edition of this newsletter. It was not a simple product claim, because that would have failed for lack of novelty.

The claim was to a recombinant DNA molecule characterised by a DNA sequence coding for a polypeptide . . . displaying HBV antigen specificity . . . when a suitable host cell transformed [therewith] is cultured etc. It was for a molecule identified partly by the way it has been made (‘recombinant DNA’) and partly by what it does.

The word ‘recombinant’ was necessary to distinguish the product from DNA isolated from humans. The word imported a process element to the claim, extending the claim to the DNA molecule made by any recombinant DNA technology process. As such the claim was construed as being to a class of products.

The specification in Biogen described only one method of making the molecule by recombinant technology and disclosed no general principle. It was easy to contemplate other methods about which the specification said nothing and which would owe nothing to the matter disclosed.

The law of sufficiency, both in the United Kingdom and in the EPO, is that a claim to a class of products is only ‘sufficient’ if every member of the class is enabled - either by empirical demonstration, or by disclosing a principle which can reasonably be expected to work across the class. In revisiting Biogen, Lord Hoffman in Lundbeck, said that, as a matter of construction, the House of Lords in Biogen (and he wrote the opinion of the House) interpreted the claim as being to a class of products which satisfied the specified conditions, one of which was that the molecule had been made by recombinant technology. He said that expression obviously includes a wide variety of possible processes.¹ The Biogen patent only disclosed one process – therefore the class of products claimed in Biogen was insufficient and the claim was invalid.





¹ What the House of Lords actually said was “The claims of the patent in suit are invalid for lack of support and/or insufficiency of because [the patent] does not enable products across the claim. It is a claim defined in terms of process, a kind of product-by-process claim, yet [the patent] enabled only one process out of the entire class of possible processes.”